Structure for preventing stacking connectors on boards from coming apart and electronic device

ABSTRACT

A structure is disclosed for preventing stacking connectors on a first and a second boards from coming apart that are fitted to each other. The first and second boards connected by said stacking connectors being fitted to each other are clamped by a clamping member. The clamping member is connected to surfaces on the first and second boards that connect to ground.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a structure for preventing stackingconnectors on boards from coming apart, and to an electronic devicehaving this structure.

2. Description of the Related Art

Heretofore, for preventing stacking connectors on boards from comingapart due to shocks, vibrations and the like, structures have been knownin the art wherein stacking connectors are retained by device housing orby cushion members that are disposed at required locations inside thehousing. Also, JP-A-2001-126810 discloses stacking connectors comprisinga locking mechanism which prevents the stacking connectors that arefitted together from moving in a direction in which one comes off fromthe other, as a means to prevent dislodgement.

However, the former approach involves wasted space that is not used tomount parts therein owing to the structure that retains the stackingconnectors. For example, when cushion members are used, space betweenthe stacking connectors will be filled up only with the cushions. Thelatter approach, on the other hand, has the drawback that it isnecessary to provide special stacking connectors and to make an extraconnection to ground, as will be later described.

A foldable radio communications device such as a portable telephone canbe constructed using stacking connectors with a flexible printed circuitboard interposed between a board for a liquid crystal display and aboard for a keyboard. In this case, a connection is also made to groundin order to prevent the flexible printed circuit board from acting as afloating metal substance to adversely affect the antennacharacteristics. This connection to ground is typically made bysoldering of the flexible printed circuit board, a conductive tape orthe like. But these are not desirable from the standpoint of workingcosts and workability. The conductive tape also has the problem that itcannot be reused.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a structure which iscapable of preventing stacking connectors on boards from coming apart,and also capable of making a connection to ground.

It is another object of the present invention to provide an electronicdevice having such a structure.

To this end, in accordance with the present invention, there is provideda structure for preventing stacking connectors on a first and a secondboards from coming apart that are fitted to each other, wherein thefirst and second boards connected by the stacking connectors beingfitted to each other are clamped by a clamping member, the clampingmember being connected to surfaces on the first and second boards thatconnect to ground.

The present invention assures that the stacking connectors is preventedfrom coming apart with a simple structure, and also improves efficiencyin mounting parts, workability, antenna characteristics, and resistanceto electrostatic breakdown.

The clamping member may be a clip member made of a metal. The use of theclip member facilitates handling and enables its reuse.

The structure may further comprise a stop member for deterring theclamping member from dropping. In this case, the stop member maypreferably be held by a stationary frame member.

A gap of a predetermined width may preferably be provided between thestop member, the frame member and the clamping member.

The above and other objects, features and advantages of the presentinvention will become apparent from the following description withreference to the accompanying drawings which illustrate examples of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a portable telephone accordingto one embodiment of the present invention;

FIG. 2 is a vertical sectional view of a keyboard of the portabletelephone illustrated in FIG. 1;

FIG. 3 is an enlarged view of a structure for preventing stackingconnector on the keyboard from coming apart; and

FIG. 4 is a view illustrating attachment of a clip.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description will hereinafter be given of an embodiment in which thepresent invention is applied to a foldable portable telephone.

Referring first to FIG. 1, the general configuration of a foldableportable telephone that employs a fixing structure for stackingconnectors according to the present invention is illustrated. Thefoldable portable telephone illustrated in FIG. 1 mainly comprises abutton manipulation section which includes front case 12 foraccommodating board 4 for a keyboard and rear cover 13, and a liquidcrystal display section which includes front case 14 for accommodatingboard 11 for a liquid crystal display and rear cover 15. Further,flexible printed circuit board 1 is arranged between board 4 for thekeyboard and board 11 for the liquid crystal display. Flexible printedcircuit board 1 is secured at one end to stacking connector 2 a to befitted into stacking connector 2 b on board 4 for the keyboard, and atthe other end to stacking connector 2 c to be fitted into stackingconnector 2 d on board 11 for the liquid crystal display. Stackingconnectors 2 a and 2 c are coupled together via a flexible strip member.Board 4 for the keyboard is electrically connected to sub-board 7 whichis fixed to board 4 through frame 8.

Next, referring to FIGS. 2 and 3, a structure will be described forpreventing the stacking connectors that connect board 1 with board 4,also shown in FIG. 1, from coming apart. After the terminals of a pairof stacking connectors 2 a, 2 b have been fitted to each other, clip 10is mounted to clamp both board 4 for the keyboard and flexible printedcircuit board 1 (see FIG. 4). Clip 10 is a conductive, resilient metalmember and is generally U-shaped with upper and lower clamping portionseach having a predetermined width, and a connecting portion whichconnects the clamping portions.

Frame 8 serves to fix sub-board 7 and is provided with stop member 9 inthe form of a claw-like protrusion to prevent clip 10 from popping outor dropping therefrom. The stop member is configured such that when clip10 slides toward stop member wall, a side end (closed end) of clip 10 iscaused to abut against the stop member to prevent clip 10 from dropping.Provided between frame 8 and stop member 9 and clip 10 is gap 16 of apredetermined width which ensures that shocks and vibrations will not betransmitted to stacking connectors 2 a, 2 b, when an external force isexerted to the portable telephone or when the portable telephone isdropped. Thus, clip 10 will not slide or come off due to externalforces, shocks, vibrations or the like.

Flexible printed circuit board 1 is further provided with surface 3 thatconnect to ground plane, in a region of the top surface thereof withwhich clip 10 comes into contact, and board 4 for the keyboard islikewise provided with surface 6 that connects to ground, in a region ofthe bottom surface thereof with which clip 10 comes into contact,thereby also making a connection to ground through mounting clip 10.

Next, referring to FIG. 4, in conjunction with FIGS. 1 to 3, a procedurewill be described for assembling the structure to prevent the stackingconnectors from coming apart. First, stacking connector 2 a on flexibleprinted circuit board 1 is fitted into stacking connector 2 b on board 4for the keyboard. FIG. 4 represents a state in which stacking connectors2 a, 2 b are fitted to each other. Then, clip 10 is attached to clampboth flexible printed circuit board 1 and board 4 for the keyboard, byusing cutout 5 for positioning, cutout 5 being provided on board 4.

Subsequently, after sub-board 7, which is electrically connected toboard 4 for the keyboard, is fixed to frame 8, as illustrated in FIG. 1,frame 8 is brought into engagement with the top surface of stackingconnector 2 a on board 4 for the keyboard. Thereafter, the otherstacking connector 2 c on flexible printed circuit board 1 is fittedinto stacking connector 2 d on board 11 for the liquid crystal display.These electrically connected boards are assembled into front cases 12,14, and rear covers 13, 15 are fitted on front cases 12, 14,respectively, thereby completing the assembling procedure.

As is apparent from the foregoing description, stacking connectors 2 a,2 b can be prevented from coming apart by clamping flexible printedcircuit board 1 and board 4 for the keyboard with clip 10. It is alsopossible to deter the stacking connectors from dropping and to improvethe antenna characteristics and resistance to electrostatic breakdown bypositively connecting surfaces 3 and 6 of flexible printed circuit board1 and board 4 for the keyboard with conductive clip 10.

Also, in addition to the ability to improve the workability, theconfiguration illustrated in the foregoing embodiment solves the problemof reusability, as compared with a conventional connection to groundwhich is made by soldering, conductive tape or the like. Furthermore,the configuration illustrated in the foregoing embodiment also makes itpossible to improve efficiency in mounting parts because space formounting parts is secured on the stacking connector by utilizing theframe.

Also, in the foregoing embodiment, a configuration is employed whereincutout 5 is provided on one end of board 4 for the keyboard, in order toimprove workability. However, board 4 for the keyboard may be providedwith a recess into which clip 10 fits, or flexible printed circuit board1 may be provided with a similar cutout, groove, or printed pattern.These may be omitted if it is recognized that the workability is notmuch affected, as a matter of course. In addition, the tip of the clipmay be configured to fit into such a recess, groove or the like, toprevent drop or slide of the clip.

While the foregoing embodiment has been described by way of example inwhich a gap is provided between frame 8 and clip 10, the width of thegap may be set depending on the device which employs a structure forpreventing the stacking connectors from coming apart, and may be zero asrequired. Alternatively, a deformable spacer member, preferably made ofa cushioning material, may be arranged between frame 8 and clip 10.

While the foregoing description has been given of an embodiment in whichthe present invention is applied to a portable telephone, the presentinvention can be equally applied to electronic devices, includingpersonal computers and PDA's (Personal Digital Assistant), which includea structure for connecting a plurality of boards (irrespective of thetype of board) using stacking connectors. Also, in view of the featuresof the present invention, it can be said that the present invention ismore preferably applicable to a fixing structure using stackingconnectors to connect a flexible printed circuit board to other boards(irrespective of whether the boards are rigid or flexible).

While preferred embodiments of the present invention have been describedusing specific terms, such description is for illustrative purposesonly, and it is to be understood that changes and variations may be madewithout departing from the spirit or scope of the following claims.

1. A structure for preventing stacking connectors on a first and asecond board from coming apart once they have been fitted to each other,each of said first and second boards having a first surface with arespective stacking connector positioned thereon and a second surfaceopposite said first surface, said stacking connector of said first boardbeing fitted into said stacking connector of said second board, each ofsaid second surfaces of said first and second boards having a firstregion that connects to ground, said structure comprising: a clampingmember for clamping said first and second boards, said clamping memberbeing connected to said first regions of said second surfaces of saidfirst and second boards that connect to ground.
 2. The structureaccording to claim 1, wherein said clamping member is a clip member madeof a metal.
 3. The structure according to claim 1, further comprising astop member for deterring said clamping member from dropping.
 4. Thestructure according to claim 3, wherein said stop member is held by astationary frame member which retains a third board.
 5. The structureaccording to claim 4, wherein a gap of a predetermined width is providedbetween said stop member and said frame member and said clamping member.6. The structure according to claim 4, further comprising a spacermember disposed between said stop member and said frame member and saidclamping member.
 7. An electronic device comprising: a first boardhaving a first surface with a respective stacking connector positionedthereon and a second surface opposite said first surface, a first regionof said second surface of said first board being connected to ground; asecond board having a first surface with a respective stacking connectorpositioned thereon and a second surface opposite said first surface, afirst region of said second surface of said second board being connectedto ground, said stacking connector of said first board being fitted intosaid stacking connector of said second board; and a clamping member forclamping said first board and said second board, said clamping member incontact with said first region of said second surface of said firstboard and in contact with said first region of said second surface ofsaid second board.
 8. The electronic device according to claim 7,wherein said second board is a board for a main body of the electronicdevice, and said first board is a flexible board for electricallyconnecting said second board with a board for a liquid crystal displaydevice, said liquid crystal display device being pivotally mounted via ahinge structure.
 9. The electronic device of claim 7, wherein saidclamping member prevents said stacking connector of said first boardfrom coming apart from said stacking connector of said second board. 10.The electronic device of claim 7, wherein said clamping member is aclip; and wherein said clip is U-shaped with an upper clamping portionin contact with said first region of said second surface of said firstboard, a lower clamping portion in contact with said first region ofsaid second surface of said second board, and a connecting portion thatconnects said upper clamping portion and said lower clamping portion.11. The electronic device of claim 10, further comprising: a framehaving a stop member that is positioned such that, if said clip slidestoward said stop member, said connecting portion of said clip abutsagainst said stop member so that said clip is prevented from poppingout.
 12. The electronic device of claim 11, wherein said frame isfurther positioned such that a gap of a predetermined width is providedbetween said frame and said clip.
 13. The electronic device of claim 11,further comprising: a deformable spacer member positioned between saidframe and said clip.
 14. The electronic device of claim 7, wherein theclamping member comprises metal.
 15. The electronic device of claim 7,further comprising: an antenna for performing radio communication. 16.The electronic device of claim 7, wherein the electronic device is afoldable portable telephone.